. >>> captain scott kelly will man the longest space flight for a u.s. astronaut. nasa will send him to the international space station for a year-long mission beginning in 2015. the current record for an american is 215 days. scott kelly is the twin brother of the retired shuttle commander mark kelly. >>> your favorite drink could be fizzling with an unexpected ailment. in tonight's health watch, how that can of soda can affect your knees. >>> we'll look at the federal budget negotiations tonight on the cbs evening news. ,,,,,,,,,,,,,, your knees. but now, a surprising factor >>> well the older you get, the creekier your knees. >> that's true. but now a surprising factor that seems to speed up the problem. sugar sodas. we'll explain the connection for you. >> reporter: sugary soft drinks have been long to provide weight gain. but the beverages might be linked to an unexpected ailment, arthritis in the knee. researchers followed more than 2,000 patients with the condition and the most common form of arthritis. doctors monitor them with x- rays of the knee every yea